すべての計算ツール

The nth term and the sum of the first n terms of an arithmetic or geometric sequence, the sum to infinity, and exact Fibonacci numbers, with a table.

Add, subtract, multiply and divide complex numbers, raise them to powers, find nth roots, and convert a + bi to polar form, with an Argand diagram.

The definite integral of any function f(x) between two limits, by adaptive Gauss–Kronrod quadrature to about 20 significant digits, with the area shaded.

Raise a number to any exponent, including fractional and negative ones, or take its square, cube or nth root, with exact simplified radicals such as 5√2.

Factor calculator: every factor and factor pair of a whole number up to 10¹⁸, its prime factorization, divisor count and sum, and perfect or abundant.

分数と帯分数の足し算・引き算・掛け算・割り算を正確に行い、既約分数に約分します。循環小数を含む小数を分数に変換できます。

Greatest common divisor (GCD, GCF or HCF) and least common multiple (LCM) of two or more whole numbers, with Euclid's algorithm step by step.

複数の関数、極座標曲線、媒介変数曲線を描画し、移動とズーム、根、交点、極値、面積の探索ができます。

The logarithm of a number to any base, including ln and log₁₀, with change-of-base steps, or the exponent x that solves bˣ = y, exact when rational.

Long division calculator that shows every step: quotient and remainder, the decimal quotient with its repeating block marked, and the fraction.

最大 6 × 6 の行列の行列式、逆行列、階数、簡約行階段形を、すべての行基本変形付きで計算。転置、積、和にも対応し、厳密な分数を使用します。

Average calculator for a list of numbers: mean, median, mode, range, count and sum, with the sorted data and the middle values highlighted.

Calculate a mod n under the floored, truncated and Euclidean conventions, modular powers a^b mod m of large numbers, and modular inverses, with steps.

The first or second derivative of any function f(x) at a point, to about 20 significant digits by Richardson extrapolation, with the tangent line drawn.

YのX%、ある数が別の数に占める割合、増加率・減少率、パーセント差、および一定の割合を加える前の元の値を計算します。

All real and complex roots of a polynomial up to degree 6, such as a cubic or quartic equation, with repeated roots found exactly and 30-digit accuracy.

Prime factorization of any whole number up to 60 digits, with a factor tree, a prime or composite verdict, its divisors and the nearest primes.

解の公式で ax² + bx + c = 0 を解きます。根号または複素数による厳密な解、判別式、頂点、対称軸、グラフを表示します。

Simplify a ratio, solve a proportion a : b = c : x for the missing term, scale a ratio to a target, or split an amount in a given ratio, exactly.

Convert numbers to Roman numerals and Roman numerals to numbers, from 1 to 3,999 (3,999,999 with overlines), with the standard form of any numeral.

小数点以下の桁数、有効数字、または最も近い10や100の倍数に丸めます。偶数丸め、負の無限大方向への丸め、正の無限大方向への丸めなど、9種類の規則に対応します。

度・ラジアン・グラードの三角関数、対数、べき乗、階乗、メモリー、計算履歴を備えたキー入力式電卓。可能な限り厳密な分数を使用します。

Scientific notation calculator: convert between decimal, scientific, E and engineering notation, and add, subtract, multiply or divide with sig-fig rules.

Union, intersection, differences and symmetric difference of two sets of numbers or words, with the Jaccard index and a Venn diagram.

Square root calculator: the root to up to 1,000 decimal places, simplest radical form (√72 = 6√2), a perfect-square check and cube or nth roots.

Solve 2 to 5 simultaneous linear equations exactly by Gauss–Jordan elimination, with every row operation shown, and detect no-solution or infinite cases.

Truth table of a Boolean expression in up to 6 variables, with the canonical sum of products, product of sums, minterms and maxterms.

Dot and cross products of two vectors in 2D or 3D, their magnitudes, the angle between them and the projection of one onto the other, with a drawing.

Weighted average calculator: enter values with weights, one pair per line, for the weighted mean, sum of weights and each value's contribution.

十進度、度分秒（DMS）、ラジアン、グラード、回転数、角分、角秒、ミリラジアンの間で角度を変換します。

長方形、三角形、台形、円、楕円、正多角形、円環など15種類の図形の面積と周長を計算し、縮尺に合わせた図を表示します。

面積、円周、半径、直径のいずれか1つから残りを計算。中心角から弧長、弦長、扇形と弓形の面積も求めます。

3点を通る円の中心、半径、面積、方程式を計算。標準形(x − h)² + (y − k)² = r²と一般形を表示します。

辺の数または1つの角度から、正多角形の内角の和、各内角と外角、対角線の数を計算します。

頂点の座標から単純多角形の面積、周長、図心を靴紐の公式で計算し、各項の計算過程を表示します。

2つの値から三平方の定理と三角比を使い、斜辺、未知の辺、2つの鋭角、面積、周長を計算します。

高さと水平距離から角度、勾配の百分率、屋根勾配（12に対するx）、斜面の長さ、垂木長さの係数を求めます。

2点の距離、中点、傾き、直線の式を傾き切片形・標準形・点傾き形で計算し、2直線の交点も求めます。

3つの測定値から辺、角度、面積、周長、高さ、内接円・外接円の半径を計算。SSAで2通りの解がある場合は両方を表示します。

度、ラジアン、グラードでsin、cos、tan、sec、csc、cotを計算。15°の整数倍での厳密値と逆関数のすべての解も表示します。

円柱、円錐、球、角錐、角柱、トーラス、楕円体など14種類の立体の体積、表面積、斜高、リットル単位の容量を計算します。

Calculate your 401(k) balance at retirement from salary, contribution rate and a two-tier employer match, with 2026 IRS limits and catch-up.

Amortization calculator: payment, dated schedule and yearly totals for monthly, biweekly or weekly payments, with principal and interest in each.

Calculate an annuity's future value from regular payments, the payout a lump sum buys over N years, or how long it lasts at a set withdrawal.

Calculate a loan's APR with fees by the Regulation Z actuarial method, the amount financed, the finance charge and the effective annual rate.

Auto loan calculator: monthly car payment with trade-in, amount owed, sales tax and fees, total interest, a payment schedule, or the price a budget buys.

Calculate European call and put prices and the Greeks (delta, gamma, theta, vega, rho) with the Black-Scholes-Merton model, including dividends.

Calculate a bond's price from its yield to maturity, or the YTM from its price, with current yield, Macaulay and modified duration and convexity.

Calculate the break-even point in units and sales revenue from fixed costs, price and variable cost, plus the volume needed for a target profit.

Canadian mortgage payment with semi-annual compounding, accelerated bi-weekly or weekly options, the CMHC insurance premium and the balance at renewal.

Calculate a monthly car lease payment from the price, residual value and money factor or APR, split into depreciation, finance charge and tax.

Calculate CD interest and maturity value from the APY or APR and compounding, convert APY to APR, and see what an early withdrawal penalty costs.

Calculate sales commission at a flat or tiered rate, total pay with base salary, the effective rate, and the sales needed to earn a target commission.

預入額と定期的な積立額の将来価値を、日次や連続複利を含む任意の複利頻度で計算します。

Calculate how long a credit card balance takes to pay off on minimum payments versus a fixed monthly payment, and the interest each costs.

最新の毎日の参考レートで 160 通貨を換算。レートの日付と 90 日間の履歴グラフを表示します。

Calculate enterprise value, equity value and value per share with a DCF: projected free cash flows plus a Gordon-growth terminal value.

Debt consolidation calculator: compare your debts with one loan — monthly payment, total interest, payoff time, APR with fees and the break-even rate.

Compare the debt snowball (smallest balance first) and avalanche (highest rate first): months to debt-free, total interest and payoff order.

Calculate your debt-to-income ratio (DTI), front-end and back-end, against lender limits, and the debt cut or income rise that reaches your target.

Calculate a depreciation schedule by straight-line, declining balance, double declining, sum-of-years' digits or units of production, with book value.

Down payment and closing costs you need, how long your savings take to reach them (or the monthly saving needed), and the PMI cost below 20% down.

FHA loan payment with the 1.75% upfront MIP, the annual MIP from HUD's current table, taxes and insurance, and a check against your county's 2026 loan limit.

Add GST, VAT or sales tax to a price, or remove it from a tax-inclusive price, with stacked state and local rates or India's CGST/SGST split.

Home equity you can borrow at your lender's CLTV limit, and HELOC payments in the interest-only draw period and the repayment period, or a fixed home equity loan.

Find how much house you can afford: the highest home price whose payment, tax, insurance, HOA and PMI fit the 28% and 36% debt-to-income limits.

Calculate income tax for India FY 2025-26 (new vs old regime), US federal 2025 and UK 2025-26, with take-home pay and marginal and effective rates.

Calculate what a purchase will cost after inflation, what your money will still buy, and your real return after inflation.

Find how much you can borrow from the monthly payment you can afford at your rate and term, and the price your down payment then buys.

住宅・自動車・個人向けローンの毎月返済額、利息総額、繰上返済を含む月ごとの返済予定表を計算します。

固定資産税、保険、住宅所有者協会費（HOA）、民間住宅ローン保険（PMI）を含む月額と、返済予定表や追加返済による節約額を試算します。

Mortgage payoff calculator: new payoff date, months and interest saved by extra monthly, yearly or one-time payments, or the extra to finish by a date.

Calculate NPV, IRR, modified IRR, payback and discounted payback for a series of periodic cash flows, with the NPV profile across rates.

Calculate US take-home pay per paycheck and per year: 2026 federal withholding (IRS Pub. 15-T), Social Security, Medicare, state tax and deductions.

Compare refinancing at your planned sale or payoff month. See payments, closing costs, remaining balances and savings with cash or financed fees.

Compare renting and buying a home: net worth from owning versus renting and investing the difference, year by year, and when buying pulls ahead.

Calculate a rental property's cap rate, NOI, monthly cash flow, cash-on-cash return and IRR, with a year-by-year projection of rent, value and equity.

Calculate how much you need to retire on inflation-adjusted expenses, the monthly saving that gets you there, and how the money runs down.

Calculate your required minimum distribution from the IRS Uniform Lifetime or joint table, your RMD starting age (73 or 75), and future RMDs.

Calculate ROI (total return) and CAGR (compound annual growth rate) from an investment's start and end values, over years or between two dates.

Calculate your 2026 Roth IRA contribution limit after the income phase-out, its growth, and whether a Roth or traditional IRA leaves more after tax.

Convert an annual salary to an hourly wage or hourly pay to salary, plus daily, weekly, biweekly, semimonthly and monthly pay.

Calculate how much to save each month to reach a savings goal by a date, or how long a monthly deposit takes to get there, with interest.

Calculate simple interest (I = P × r × t) and the maturity amount on a principal for a term in years, months or days.

毎月の投資信託積立（SIP）の満期価値を試算します。年ごとの増額や、目標に必要な積立額の計算にも対応します。

Calculate your average cost per share across several buys, unrealized profit and return, and the position size for your risk and stop loss.

Student loan calculator: payment, total interest and payoff date on the federal standard, tiered or extended plan or a custom term, with extra payments.

Solve for the future value, present value, interest rate or time of a lump sum from the other three, with any compounding, including continuous.

VA loan payment with the VA funding fee from the current table (first or later use, by down payment), the financed loan amount, taxes and insurance.

Calculate XIRR, the annualized return on cash flows made on irregular dates, and XNPV at your discount rate, matching Excel's actual/365 method.

Army body fat standard for 2026: your waist-to-height ratio, pass or fail against 0.55 (AD 2026-13), the largest passing waist for your height and margin.

Blood alcohol content (BAC) estimate by the Widmark formula from drinks, body weight and time, with the elimination curve and time back to zero.

Blood pressure category (AHA/ACC) for a systolic/diastolic reading, from normal to stage 2 and severe hypertension, with pulse pressure and MAP.

Glucose from mg/dL to mmol/L and back, and HbA1c to estimated average glucose (eAG) and IFCC mmol/mol, with ADA categories.

メートル法またはヤード・ポンド法の身長と体重からBMIを計算し、WHOの成人向け区分と身長に応じた健康的な体重範囲を表示します。

Mifflin-St Jeor、Harris-Benedict、Katch-McArdleの式で基礎代謝量（BMR）を推定し、5段階の活動量に応じた1日の必要カロリー（TDEE）を計算します。

米海軍の周囲長法、Jackson-Pollockの3点・7点皮下脂肪厚法、またはBMIから体脂肪率を推定し、脂肪量・除脂肪量とACE区分を表示します。

Body surface area (BSA) in m² from height and weight by the Mosteller, DuBois and Haycock formulas, with the spread between them.

How much caffeine is left in your body from up to three doses, based on its half-life, and when the level drops below an amount you choose.

減量・維持・増量のための1日の目標カロリーと、1日および1食あたりのたんぱく質・炭水化物・脂質のグラム数を計算します。

Calories burned by an activity from its MET value in the Compendium of Physical Activities, your body weight and the time spent.

Estimated conception date and fertile window from a due date, the last period or an ultrasound, with the likely range for each dating method.

Cycling power-to-weight (W/kg), speed and pace, or swimming pace per 100 m and 100 yd with your SWOLF score.

Dose by weight from a mg/kg rate and body weight, capped at the single and daily maximum, with the liquid volume in mL for a given strength.

eGFR from serum creatinine (mg/dL or µmol/L), age and sex by the race-free CKD-EPI 2021 equation, with optional cystatin C and the KDIGO G1–G5 stage.

Heart rate zones from your maximum heart rate (220 − age, Tanaka, Gulati for women, or measured) by the Karvonen or percent-of-max method, with a target heart rate.

身長と性別からDevine、Robinson、Miller、Hamwiの式で理想体重を計算し、健康的なBMIに対応する体重範囲を表示します。

Lean body mass (LBM) from height, weight and sex by the Boer, James and Hume formulas, with the implied body fat percentage.

One-rep max (1RM) from a set of reps with the Epley, Brzycki, Lombardi and O'Conner equations, plus training loads from 50 % to 100 %.

Ovulation date, fertile window and next period for the coming cycles, from the first day of your last period and your cycle length.

Next period date and the following 5 predicted periods, with each cycle's fertile window and ovulation day, from your last period and average cycle length.

Pregnancy due date from the last period, conception date or IVF transfer, with today's gestational age, trimester and milestones (ACOG).

Recommended pregnancy weight gain by pre-pregnancy BMI (IOM 2009), for singletons or twins, with the weekly rate and a week-by-week chart of your gain.

Daily protein intake in grams from body weight, goal and training level, using published g/kg ranges, with a per-meal split.

Running pace per km or mile from distance and time, or finish time or distance from pace, with even splits and Riegel race predictions.

Bedtimes for a wake-up time, or wake-up times for a bedtime, counted in 90-minute sleep cycles plus the time it takes to fall asleep.

Steps to distance in km and miles from a step length based on your height or measured, with walking time and calories from the ACSM equation.

VO2 max from the Cooper 12-minute run, the Rockport 1-mile walk or the resting heart-rate ratio, rated against Cooper Institute norms for age and sex.

Waist-to-hip ratio and waist-to-height ratio from tape measurements, with the WHO risk cut-offs, the NICE bands and the WHO waist size category.

Daily water intake in litres, glasses and fl oz from body weight, exercise and climate, compared with EFSA and US adequate intakes.

開始日から指定した日数、週数、月数、年数または営業日数だけ前後の日付を求め、曜日と暦日での移動日数を表示します。

生年月日から任意の日付での正確な年齢を年月日で計算し、次の誕生日や月・週・日・時間単位の年齢も表示します。

The deadline N business days after or before a start date, skipping weekends and the holidays you list, with the calendar days it spans.

Convert a Gregorian date to Hijri (Umm al-Qura and tabular), Hebrew, Persian, Indian national (Saka) and Julian dates, or a Julian date back.

任意のタイムゾーンの日時までの残り、または経過した日・時・分・秒をリアルタイムで表示し、時刻変更も考慮します。

Day of the week for any date, past or future: the weekday in the Gregorian calendar, worked through step by step with Zeller's congruence.

2つの日付の間隔を日数、年月日、週、時間で計算します。週末と指定した祝日を除く営業日数にも対応します。

Calculate work hours, breaks and weekly timesheets. Use dates and a time zone for overnight shifts across daylight-saving changes and repeated hours.

Leap year checker: whether a year has 366 days under the Gregorian rule, which test decides it, and the previous and next leap years.

Military time converter: 12-hour to 24-hour time and back, how it is spoken, time-zone letters with the Zulu equivalent, and a full-day chart.

Sunrise and sunset times for any place and date, with solar noon, day length and civil twilight, worked out with NOAA's solar calculator method.

Add and subtract hours, minutes and seconds from a list of durations, with the total as H:MM:SS, decimal hours, minutes and seconds.

1つのタイムゾーンの時刻を最大12の別の地域の現地時刻に変換します。夏時間を適用し、会議の予定表も表示します。

Unix timestamp converter: epoch seconds, milliseconds, microseconds or nanoseconds to an ISO 8601 UTC date and local time, and dates back to epoch time.

Week number for any date: ISO 8601 week and week-numbering year, US week number, day of the year, days left in the year and the quarter.

Convert g-force to m/s², m/s² to g, ft/s² and gal (cm/s²), using standard gravity g₀ = 9.80665 m/s² exactly.

エーカー（ac）→ ヘクタール（ha）。正確な換算係数による換算に、換算表と計算手順を添えています。

エーカー（ac）→ 平方フィート（ft²）。正確な換算係数による換算に、換算表と計算手順を添えています。

度とラジアンを相互に換算し、グラード、角分、角秒、回転、ミリラジアンにも対応。πは50桁で計算します。

平方フィートから平方メートル、エーカーからヘクタール、平方フィートからインドの土地単位（グンタ、セント、ビガ、マルラ、カナル、グラウンド）へ、明示された係数で換算します。

バール（bar）→ ポンド毎平方インチ（psi）。正確な換算係数による換算に、換算表と計算手順を添えています。

センチメートル（cm）→ フィート（ft）。正確な換算係数による換算に、換算表と計算手順を添えています。

センチメートル（cm）→ インチ（in）。正確な換算係数による換算に、換算表と計算手順を添えています。

センチメートル（cm）→ メートル（m）。正確な換算係数による換算に、換算表と計算手順を添えています。

センチメートル（cm）→ ミリメートル（mm）。正確な換算係数による換算に、換算表と計算手順を添えています。

Convert clothing sizes between US, UK, EU, German, Italian and Japanese labels for women's dresses and tops, men's suits and shirt collars.

ルート要素と親要素のフォントサイズ、および DPI を使って px を rem、em、pt、パイカ、インチ、mm に換算します。CSS では 1 in = 96 px = 72 pt と定義されています。

King Arthur BakingとUSDAの重量表を使い、小麦粉、砂糖、バターなど27種類の製菓材料でカップとグラムを相互換算します。

GB から MB、TB から GB、GiB から GB に換算します。十進接頭辞（kB、MB、GB、TB）と二進接頭辞（KiB、MiB、GiB、TiB）を区別し、ビットとバイトにも対応します。

Mbps から MB/s、Gbps から MB/s、kbps から kB/s に換算します。通信速度はビット毎秒、ファイルサイズやダウンロード表示はバイトで表されます。

摂氏度（°C）→ 華氏度（°F）。正確な式による換算に、換算表と計算手順を添えています。

摂氏度（°C）→ ケルビン（K）。正確な式による換算に、換算表と計算手順を添えています。

華氏度（°F）→ 摂氏度（°C）。正確な式による換算に、換算表と計算手順を添えています。

華氏度（°F）→ ケルビン（K）。正確な式による換算に、換算表と計算手順を添えています。

Convert g/cm³ to kg/m³, kg/m³ to lb/ft³ and lb/gal (ppg), and g/mL to kg/L, with exact factors from the 1959 pound and foot.

Calculate how long a file takes to download or upload from its size in MB, GB or TB and your internet speed in Mbps, allowing for protocol overhead.

ジュール、カロリー、英熱量、電子ボルトの正確な定義を使い、kWh から BTU、カロリーからジュール、kcal から kJ、サームから kWh に換算します。

フィート（ft）→ センチメートル（cm）。正確な換算係数による換算に、換算表と計算手順を添えています。

フィート（ft）→ インチ（in）。正確な換算係数による換算に、換算表と計算手順を添えています。

フィート（ft）→ メートル（m）。正確な換算係数による換算に、換算表と計算手順を添えています。

フィート（ft）→ マイル（mi）。正確な換算係数による換算に、換算表と計算手順を添えています。

米ガロンと立方フィートの正確な値で、ポンプ・配管・換気のL/minからgpm、gpmからL/min、cfmからm³/h、m³/hからL/sへの換算を行います。

Convert kgf to newtons, lbf to N and kN to kgf or lbf, using standard gravity (9.80665 m/s²) and the exact pound-force of 4.4482216152605 N.

Convert rpm to Hz, Hz to rpm, BPM to Hz, GHz to MHz and hertz to radians per second (ω = 2πf), from Hz to THz.

米ガロンと英ガロンに対応し、mpg、L/100 km、km/L を相互換算します。式：L/100 km = 235.215 ÷ US mpg または 282.481 ÷ UK mpg。

ギガバイト（GB）→ メガバイト（MB）。正確な換算係数による換算に、換算表と計算手順を添えています。

ギガバイト（GB）→ テラバイト（TB）。正確な換算係数による換算に、換算表と計算手順を添えています。

グラム（g）→ キログラム（kg）。正確な換算係数による換算に、換算表と計算手順を添えています。

グラム（g）→ オンス（oz）。正確な換算係数による換算に、換算表と計算手順を添えています。

グラム（g）→ ポンド（lb）。正確な換算係数による換算に、換算表と計算手順を添えています。

ヘクタール（ha）→ エーカー（ac）。正確な換算係数による換算に、換算表と計算手順を添えています。

厳密に 2.54 cm と定義されたインチを使い、身長を cm とフィート・インチの間で、体重を kg からポンドまたはストーン・ポンドに換算します。

英馬力（hp）→ キロワット（kW）。正確な換算係数による換算に、換算表と計算手順を添えています。

インチ（in）→ センチメートル（cm）。正確な換算係数による換算に、換算表と計算手順を添えています。

インチ（in）→ フィート（ft）。正確な換算係数による換算に、換算表と計算手順を添えています。

インチ（in）→ ミリメートル（mm）。正確な換算係数による換算に、換算表と計算手順を添えています。

ケルビン（K）→ 摂氏度（°C）。正確な式による換算に、換算表と計算手順を添えています。

ケルビン（K）→ 華氏度（°F）。正確な式による換算に、換算表と計算手順を添えています。

キロカロリー（kcal）→ キロジュール（kJ）。正確な換算係数による換算に、換算表と計算手順を添えています。

キログラム（kg）→ グラム（g）。正確な換算係数による換算に、換算表と計算手順を添えています。

キログラム（kg）→ ポンド（lb）。正確な換算係数による換算に、換算表と計算手順を添えています。

キログラム（kg）→ ストーン（st）。正確な換算係数による換算に、換算表と計算手順を添えています。

キロジュール（kJ）→ キロカロリー（kcal）。正確な換算係数による換算に、換算表と計算手順を添えています。

キロメートル毎時（km/h）→ メートル毎秒（m/s）。正確な換算係数による換算に、換算表と計算手順を添えています。

キロメートル毎時（km/h）→ マイル毎時（mph）。正確な換算係数による換算に、換算表と計算手順を添えています。

キロメートル（km）→ マイル（mi）。正確な換算係数による換算に、換算表と計算手順を添えています。

キロパスカル（kPa）→ ポンド毎平方インチ（psi）。正確な換算係数による換算に、換算表と計算手順を添えています。

キロワット（kW）→ 英馬力（hp）。正確な換算係数による換算に、換算表と計算手順を添えています。

ノット（kn）→ マイル毎時（mph）。正確な換算係数による換算に、換算表と計算手順を添えています。

Convert lakh and crore to million and billion, and write any number in words in the Indian and international systems, or turn words back into digits.

マイルからkm、フィートからメートル、インチからcmのほか、16種類の長さ単位を正確な係数で換算します。5 ft 11 inのようなフィートとインチの混合入力にも対応。

100キロメートル当たりリットル（L/100 km）→ マイル毎米ガロン（mpg (US)）。正確な式による換算に、換算表と計算手順を添えています。

リットル（L）→ ミリリットル（mL）。正確な換算係数による換算に、換算表と計算手順を添えています。

リットル（L）→ 米カップ（cup）。正確な換算係数による換算に、換算表と計算手順を添えています。

リットル（L）→ 米ガロン（gal）。正確な換算係数による換算に、換算表と計算手順を添えています。

メガビット毎秒（Mbit/s）→ メガバイト毎秒（MB/s）。正確な換算係数による換算に、換算表と計算手順を添えています。

メガバイト（MB）→ ギガバイト（GB）。正確な換算係数による換算に、換算表と計算手順を添えています。

メートル毎秒（m/s）→ キロメートル毎時（km/h）。正確な換算係数による換算に、換算表と計算手順を添えています。

メートル（m）→ センチメートル（cm）。正確な換算係数による換算に、換算表と計算手順を添えています。

メートル（m）→ フィート（ft）。正確な換算係数による換算に、換算表と計算手順を添えています。

メートル（m）→ インチ（in）。正確な換算係数による換算に、換算表と計算手順を添えています。

メートル（m）→ ヤード（yd）。正確な換算係数による換算に、換算表と計算手順を添えています。

メートルトン（t）→ ポンド（lb）。正確な換算係数による換算に、換算表と計算手順を添えています。

マイル毎時（mph）→ キロメートル毎時（km/h）。正確な換算係数による換算に、換算表と計算手順を添えています。

マイル（mi）→ フィート（ft）。正確な換算係数による換算に、換算表と計算手順を添えています。

マイル（mi）→ キロメートル（km）。正確な換算係数による換算に、換算表と計算手順を添えています。

ミリリットル（mL）→ リットル（L）。正確な換算係数による換算に、換算表と計算手順を添えています。

ミリリットル（mL）→ 米カップ（cup）。正確な換算係数による換算に、換算表と計算手順を添えています。

ミリリットル（mL）→ 米液量オンス（fl oz）。正確な換算係数による換算に、換算表と計算手順を添えています。

ミリメートル（mm）→ センチメートル（cm）。正確な換算係数による換算に、換算表と計算手順を添えています。

ミリメートル（mm）→ インチ（in）。正確な換算係数による換算に、換算表と計算手順を添えています。

ニュートンメートル（N·m）→ ポンドフィート（lbf·ft）。正確な換算係数による換算に、換算表と計算手順を添えています。

オンス（oz）→ グラム（g）。正確な換算係数による換算に、換算表と計算手順を添えています。

オンス（oz）→ ポンド（lb）。正確な換算係数による換算に、換算表と計算手順を添えています。

ポンドフィート（lbf·ft）→ ニュートンメートル（N·m）。正確な換算係数による換算に、換算表と計算手順を添えています。

ポンド（lb）→ キログラム（kg）。正確な換算係数による換算に、換算表と計算手順を添えています。

ポンド（lb）→ オンス（oz）。正確な換算係数による換算に、換算表と計算手順を添えています。

ポンド（lb）→ ストーン（st）。正確な換算係数による換算に、換算表と計算手順を添えています。

hp と kW、ワットと馬力、BTU/h と冷凍トンを換算します。機械馬力（745.7 W）と仏馬力（735.5 W）に対応しています。

タイヤ、気象、血圧の測定値について、psi から bar、bar から psi、kPa、atm、hPa、mmHg、inHg に換算し、正確な換算係数の連鎖を示します。

ポンド毎平方インチ（psi）→ バール（bar）。正確な換算係数による換算に、換算表と計算手順を添えています。

ポンド毎平方インチ（psi）→ キロパスカル（kPa）。正確な換算係数による換算に、換算表と計算手順を添えています。

Convert shoe sizes between US men's and women's, UK, EU, India, Japan and Mondopoint via foot length, using the ISO/TS 19407 formulas.

Convert between SI metric prefixes such as giga, mega, kilo, milli, micro and nano, from quecto (10⁻³⁰) to quetta (10³⁰), including the 2022 additions.

正確な係数で mph から km/h、km/h から mph、m/s、ノットへ換算します。ft/s、海面高度のマッハ数、光速にも対応します。

平方フィート（ft²）→ エーカー（ac）。正確な換算係数による換算に、換算表と計算手順を添えています。

平方フィート（ft²）→ 平方メートル（m²）。正確な換算係数による換算に、換算表と計算手順を添えています。

平方メートル（m²）→ 平方フィート（ft²）。正確な換算係数による換算に、換算表と計算手順を添えています。

ストーン（st）→ キログラム（kg）。正確な換算係数による換算に、換算表と計算手順を添えています。

ストーン（st）→ ポンド（lb）。正確な換算係数による換算に、換算表と計算手順を添えています。

°F = °C × 9/5 + 32 で摂氏と華氏を換算し、両方からケルビンへ変換します。ランキンとレオミュールにも対応し、絶対零度未満は受け付けません。

テラバイト（TB）→ ギガバイト（GB）。正確な換算係数による換算に、換算表と計算手順を添えています。

365.2425日のグレゴリオ暦年を使い、分から時間、時間から日、週から日、年から秒へ変換します。ナノ秒から千年まで対応します。

トルクレンチやボルトの仕様に合わせ、N·m と lb-ft、lb-in、kgf·m を換算します。正確な関係 1 lbf·ft = 1.3558179483314004 N·m を使います。

米カップ（cup）→ ミリリットル（mL）。正確な換算係数による換算に、換算表と計算手順を添えています。

米カップ（cup）→ 米液量オンス（fl oz）。正確な換算係数による換算に、換算表と計算手順を添えています。

米カップ（cup）→ 米大さじ（tbsp）。正確な換算係数による換算に、換算表と計算手順を添えています。

米液量オンス（fl oz）→ ミリリットル（mL）。正確な換算係数による換算に、換算表と計算手順を添えています。

米液量オンス（fl oz）→ 米カップ（cup）。正確な換算係数による換算に、換算表と計算手順を添えています。

米ガロン（gal）→ リットル（L）。正確な換算係数による換算に、換算表と計算手順を添えています。

マイル毎米ガロン（mpg (US)）→ 100キロメートル当たりリットル（L/100 km）。正確な式による換算に、換算表と計算手順を添えています。

米パイント（pt）→ 米カップ（cup）。正確な換算係数による換算に、換算表と計算手順を添えています。

米クォート（qt）→ リットル（L）。正確な換算係数による換算に、換算表と計算手順を添えています。

米ショートトン（ton (US)）→ ポンド（lb）。正確な換算係数による換算に、換算表と計算手順を添えています。

米大さじ（tbsp）→ ミリリットル（mL）。正確な換算係数による換算に、換算表と計算手順を添えています。

米大さじ（tbsp）→ 米カップ（cup）。正確な換算係数による換算に、換算表と計算手順を添えています。

米大さじ（tbsp）→ 米小さじ（tsp）。正確な換算係数による換算に、換算表と計算手順を添えています。

米小さじ（tsp）→ ミリリットル（mL）。正確な換算係数による換算に、換算表と計算手順を添えています。

米小さじ（tsp）→ 米大さじ（tbsp）。正確な換算係数による換算に、換算表と計算手順を添えています。

ガロンをリットル、カップをmL、液量オンスをmLへ正確に換算し、米国と英国のガロン・パイント・液量オンスを区別します。

1959年のポンドの正確な定義でkgとポンド、ストーンとkg、オンスとグラムを換算します。トン、カラット、トロイオンス、トラにも対応します。

ヤード（yd）→ メートル（m）。正確な換算係数による換算に、換算表と計算手順を添えています。

Light travel time for any distance, apparent and absolute magnitude from the distance modulus, and redshift to recession velocity (relativistic Doppler).

Centripetal force and acceleration from mass, speed and radius; rpm to rad/s and period; moment of inertia of nine shapes; torque from force and lever arm.

Solve C₁V₁ = C₂V₂ for any dilution variable, get molarity, % w/v and ppm from a weighed mass, the mass to weigh for a solution, or molality.

Electricity cost of running an appliance per hour, day, month and year, from its wattage, hours of use and your price per kWh (unit).

Solve Newton's second law F = ma for force, mass or acceleration, or find acceleration, normal force and friction for a block on an inclined plane.

Convert grams to moles and particles for any chemical formula, and find the limiting reagent, theoretical yield and leftover excess of a balanced reaction.

Half-life calculator: amount left, starting amount, elapsed time or half-life from N = N₀·2^(−t/t½), with carbon-14 and other isotope presets.

Horsepower from torque and rpm (hp = lb-ft × rpm ÷ 5252) or from quarter-mile ET and trap speed, with crank vs wheel horsepower and drivetrain loss.

Solve the ideal gas law PV = nRT for pressure, volume, moles or temperature in any units, or find a new state with the combined gas law.

Kinematics calculator for the SUVAT equations: enter three of displacement, initial and final velocity, acceleration and time to get the other two.

Kinetic energy (½mv²), potential energy (mgh), spring energy, work (Fd cos θ) and power (W/t), solved for any variable, plus the speed after a drop.

Molar mass in g/mol and mass percent composition of any chemical formula, with brackets and hydrates such as CuSO4·5H2O, from IUPAC 2021 atomic weights.

Momentum and collision calculator: final velocities, total momentum and kinetic energy lost in an elastic, inelastic or partly elastic head-on collision.

Ohm's law calculator: enter any two of voltage, current, resistance and power to get the other two, shown in the units you pick (mA, kΩ…).

Orbital velocity and period, escape velocity, surface gravity, your weight on the Moon or Mars, and the gravitational force between two masses.

Percent error from measured and accepted values, and uncertainty propagation through sums, products, quotients and powers, in quadrature or worst case.

Calculate pH, pOH, [H⁺] and [OH⁻] from a concentration, a strong acid or base, a weak acid's Ka or pKa, or a Henderson–Hasselbalch buffer.

Projectile motion calculator: range, maximum height, time of flight and impact speed for any launch angle and height, on Earth or other worlds, with drag.

RC and RL time constant and the time to charge or discharge to any percent; series RLC resonant frequency, impedance, phase, Q factor and bandwidth.

Resistor colour code calculator for 4, 5 and 6-band resistors: colours to ohms and tolerance, or a value to its bands, snapped to E12, E24 or E96.

Series and parallel resistor calculator: total resistance of any number of resistors, plus capacitors or inductors in series or parallel.

Heat energy from Q = mcΔT (solve for heat, mass, final temperature or specific heat), latent heat Q = mL for melting or boiling, and Carnot efficiency.

Thin lens and mirror equation for image distance, object distance or focal length, with magnification; Snell's law refraction and critical angle.

Voltage divider output, or R1 or R2 for a target voltage; the current-limiting resistor for LEDs with its nearest E12 value and power rating.

Voltage drop over a DC, single-phase or three-phase cable run, plus AWG wire size to diameter, mm², kcmil and resistance per km, and back.

Convert wavelength to frequency and photon energy, or back, with c = fλ and E = hf, and see where the wave sits in the electromagnetic spectrum.

Binomial distribution calculator: exact P(X = k), P(X ≤ k), tails and ranges for binomial, Poisson, geometric, negative binomial and hypergeometric.

Chi-square test calculator for goodness of fit and independence in a contingency table: χ², p-value, expected counts and Cramér's V.

Confidence interval calculator for a mean (t or z), a proportion (Wilson or Wald) or a difference of two means, with the margin of error and both bounds.

Correlation coefficient calculator: Pearson's r or Spearman's rank correlation for paired data, with r², a t statistic and a two-sided p-value.

Descriptive statistics calculator: mean, median, mode, standard deviation, variance, quartiles, IQR, outliers, skewness and kurtosis, with a histogram.

Exact probability of dice sums, coin-flip heads and streaks, drawing special cards from a deck and each 5-card poker hand, as a fraction and 1 in N.

Calculate expected value E[X], variance and standard deviation for a bet, game or decision from its outcomes and their probabilities or weights.

Grade curve calculator: rescale a class's scores to a target mean and standard deviation, or add flat points, with z-scores and percentile ranks.

Linear regression calculator: least-squares line of best fit with R², standard errors, p-values and predictions, plus polynomial and exponential fits.

Normal distribution calculator: z-scores, the probability below, above or between values, and the value at any percentile (inverse normal).

Convert odds between fractional, decimal and American (moneyline) formats and get the implied probability, worked in exact fractions.

One-way ANOVA calculator: the F statistic, p-value, sums of squares, mean squares and η² for two or more groups, with the full ANOVA table.

Calculate nCr and nPr exactly: combinations and permutations with or without repetition, for poker hands, lottery odds and PIN codes.

Calculate P(A or B), P(A and B) and P(A | B) for two events, or apply Bayes' theorem to a test result, with a probability tree and Venn diagram.

Generate random numbers from a seed: integers in a range, decimals, lottery-style draws without repeats and dice rolls, repeatable with xoshiro256**.

Sample size calculator for surveys and studies: n for a margin of error on a proportion or mean, and the per-group n for a target power.

t-test calculator for one-sample, two-sample (Welch or pooled) and paired tests, plus z-tests for a mean or proportion: p-value, critical value, decision.

t, chi-square and F distribution calculator: tail areas, p-values, densities and critical values, plus exponential and uniform distributions.

Air conditioner size for a room in BTU/h, tons and kW from floor area, ceiling height, insulation, sun and occupants, beside the Energy Star chart.

Board foot calculator: board feet, linear feet, volume and cost for a stack of lumber, at nominal size and at the dressed size of a 2x4, 2x6 and more.

Brick calculator: bricks or blocks for a wall from its size, openings, unit size and joint, with count per m² or ft², mortar volume and waste.

Total cost of owning a car over 1–15 years: depreciation, fuel, insurance, maintenance and loan interest, per year, per km and per mile.

Calculate concrete volume and bags for slabs, footings, columns or steps. Compare bag and ready-mix quotes with delivery fees, minimums and order increments.

Deck boards, joists and screws or hidden clips for a rectangular deck, from its size, joist spacing, board width, gap and waste allowance.

Drywall sheets for a room's walls and ceiling after doors and windows, with screws, joint tape and compound, for 4 × 8 ft or metric plasterboard.

Breaker size for one circuit: total watts and amps from a list of appliances, with the NEC 125% continuous-load rule and NEC or IEC breaker ratings.

EV charging cost and time between two battery levels at any charger power, with range added and cost per 100 km or miles against petrol.

Fence calculator: posts, rails, pickets and bags of concrete for a straight fence run, from its length, post spacing, picket width and gap.

Tile calculator: tiles and boxes for a floor or wall from room size, tile size, grout joint and waste allowance, plus grout in litres and kg.

Gravel calculator: cubic metres, cubic yards, tonnes, bags and truck loads of gravel, sand, topsoil or mulch for an area and depth.

Paint calculator: litres, US gallons and whole cans of paint and primer for a room, from wall area minus doors and windows, coats and coverage.

Pool volume in gallons, litres and m³ for rectangular, round or oval pools and water tanks, with fill time and the chlorine dose to raise ppm.

Roof area, squares and shingle bundles from building size and pitch, with underlayment rolls, ridge cap and the IRC minimum slope check.

Floor area in square metres and square feet, wall area, perimeter and volume for one or more rectangular rooms or an L-shaped room.

How many solar panels you need: system size in kW, panel count, yearly kWh, installed cost and payback from your use and peak sun hours.

Number of steps, riser height, tread depth, stringer length and stair angle from total rise and run, checked against IRC riser and tread limits.

Fuel cost of a trip from distance, mpg or L/100 km and fuel price, with tolls, a round-trip option and the cost split per person.

Wallpaper calculator: rolls to buy from wall width and height, roll size, pattern repeat and trimming, counted as full-height drops per roll.

Bra size calculator: band and cup from underbust and bust in inches or cm, in US, UK, EU, FR/BE and AU sizes, with sister sizes and the method stated.

Convert text to title case, sentence case, UPPER or lower case, or to camelCase, snake_case and kebab-case, with character and word counts.

Sale price after one or more percent-off discounts, and selling price from cost using a markup or a profit margin, with each converted to the other.

Dog years and cat years calculator: a pet's age in human years from the AAHA/Zoetis size chart or the International Cat Care table, for fun comparisons.

Gas mileage calculator: MPG (US and UK), L/100 km and km/L from odometer readings and fuel added, cost per mile, and a fill-up log with trend chart.

Golf handicap calculator: World Handicap System Handicap Index from your score differentials (best 8 of 20), then course and playing handicap for any tee.

GPA calculator: credit-weighted grade point average on the 4.0 scale from letter grades, plus percentage-to-GPA and CBSE CGPA-to-percentage conversions.

Grade calculator for weighted categories: your current course grade, and the score you need on the final exam or remaining work to reach a target.

Expense splitter: enter who paid what to get each person's equal share and who owes whom, settled with the fewest possible payments.

For entertainment only: a love compatibility score from 0 to 100 made from two names. The same pair always gets the same score; it predicts nothing.

Convert oven temperatures between °C, °F, fan oven and gas mark, and work out how much to scale a recipe for a different round, square or rectangular pan.

PPI calculator: pixel density from resolution and diagonal, plus screen width and height, aspect ratio, dot pitch and the distance where pixels blend.

Scale a recipe to any number of servings: each ingredient is multiplied by new ÷ original servings, with cups and spoons shown as kitchen fractions.

Tip calculator for any bill: tip on the pre-tax or after-tax total, then split it evenly or by shares, with each person's share rounded up.

Tire diameter, sidewall height and revolutions per km from a size such as 225/45R17, and the speedometer error when you change tire sizes.

Trip budget from daily spending per person, fixed costs and a contingency, plus how many days of jet lag to expect after crossing time zones.

Unit price calculator: compare up to four pack sizes by price per kg, litre, 100 g, ounce or item to see which is cheapest and by how much.

Split a wedding or event budget across categories by percentage or fixed amount, with the cost per guest and what is left to allocate.

Word counter: words, characters with and without spaces, sentences and paragraphs, plus reading time at 238 wpm and speaking time at 150 wpm.

Find the aspect ratio of any resolution, such as 1920 × 1080 = 16:9, resize it to a new width or height, or fit it in a screen with letterbox bars.

Download or upload time for a file at a given speed, the data a link moves in a set time, and a website's monthly bandwidth from page views.

Encode or decode Base64, URL-safe Base64, URL percent-encoding, HTML entities, hex bytes and Unicode code points, with UTF-8 and UTF-16 byte counts.

Operation counts and running times for O(1), O(log n), O(n), O(n log n), O(n²), O(n³), O(2ⁿ) and O(n!) at your input size, on a log-scale chart.

Convert numbers between binary, decimal, hex, octal and any base 2–36, including fractions, repeating digits and two's-complement bits for negatives.

Bitwise AND, OR, XOR, NOT, NAND, NOR, shifts and rotates on 8- to 64-bit integers, shown in decimal, hex and binary with a bit-by-bit grid.

How a color looks with protanopia, deuteranopia or tritanopia (red, green or blue color blindness), using the Machado et al. (2009) model.

Convert a color from HEX to RGB, HSL, HSV, CMYK, CIE Lab and OKLCH or back, and find its nearest CSS named color and relative luminance.

Check the WCAG 2.2 contrast ratio between a text color and its background, with AA and AAA pass or fail for normal text, large text and UI parts.

Generate complementary, analogous, triadic, split-complementary, tetradic or monochromatic color palettes from one base color, with HEX codes.

Translate a five-field cron expression or crontab line into plain English and list its next run times after any start date and time, in UTC.

Generate MD5, SHA-1, SHA-256, SHA-512 and CRC-32 hashes of any text, check them against a published checksum, and see the avalanche effect.

Format (pretty-print) or minify JSON and validate it against RFC 8259, with the line and column of any syntax error explained in plain words.

Check a password's entropy in bits and its average brute-force crack time at a chosen guess rate, or generate a password from a reproducible seed.

Calculate usable RAID capacity, parity or mirror overhead and how many drive failures RAID 0, 1, 5, 6 and 10 survive, in TB and the TiB Windows shows.

Find the network address, broadcast, usable host range and host count of any IPv4 or IPv6 CIDR block, with netmask, wildcard and equal subnets.

Generate reproducible UUID v4 and v7 values from a seed, or validate any UUID or GUID and decode its version, variant and embedded timestamp.

Air pressure at altitude from the standard atmosphere, with temperature, air density and the boiling point of water, or the altitude for a given pressure.

Life path number calculator: a birth date reduced to a numerology number from 1 to 9, or the master numbers 11, 22 and 33, with every step shown.

Moon phase for any date and time: the phase name, percentage illuminated and moon age in days, with the dates of the next new and full moons.

Carbon footprint calculator: yearly tonnes of CO₂e from driving, flights, train and bus, home electricity and diet, using UK government emission factors.

Rainwater harvesting calculator: yearly litres or gallons a roof collects from its area, rainfall and efficiency, and the share of household use it covers.

Wind chill and heat index calculator: the feels-like temperature from the NWS formulas, plus dew point, frostbite risk and heat-stress level.

Zodiac sign calculator: your star sign and its element from a birth date, plus the Chinese zodiac animal, element and yin or yang. For entertainment.